Rating: 
Hill’s Prescription Diet W/D dog food is not rated due to its intentional therapeutic design.
The Hill’s Prescription Diet W/D product line includes two dry dog foods.
However, since we’re unable to locate AAFCO nutritional adequacy statements for these dog foods on the company’s website, it’s impossible for us to report specific life stage recommendations for these recipes.
The following is a list of recipes available at the time of this review.
- Hills Prescription Diet W/D Low Fat-Glucose Management-Gastrointestinal
- Hills Prescription Diet W/D Low Fat-Glucose Management-Gastrointestinal with Chicken
Hills Prescription Diet W/D Low Fat-Glucose Management-Gastrointestinal was selected to represent both products in the line for this review.
Hill's Prescription Diet W/D Low Fat-Glucose Management-GI
Dry Dog Food
Estimated Dry Matter Nutrient Content
Ingredients: Whole grain corn, powdered cellulose, chicken by-product meal, corn gluten meal, chicken liver flavor, soybean mill run, soybean oil, dried beet pulp, lactic acid, soybean meal, caramel (color), potassium chloride, calcium sulfate, flaxseed, l-lysine, choline chloride, calcium carbonate, vitamins (vitamin E supplement, l-ascorbyl-2-polyphosphate (source of vitamin C), niacin supplement, thiamine mononitrate, vitamin A supplement, calcium pantothenate, biotin, vitamin B12 supplement, pyridoxine hydrochloride, riboflavin supplement, folic acid, vitamin D3 supplement), taurine, minerals (ferrous sulfate, zinc oxide, copper sulfate, manganous oxide, calcium iodate, sodium selenite), iodized salt, l-tryptophan, l-carnitine, l-threonine, mixed tocopherols added to retain freshness, citric acid added to retain freshness, phosphoric acid, beta-carotene, rosemary extract
Fiber (estimated dry matter content) = 16.4%
Red items when present indicate controversial ingredients
| Estimated Nutrient Content | |||
|---|---|---|---|
| Method | Protein | Fat | Carbs |
| Guaranteed Analysis | 19% | 9% | NA |
| Dry Matter Basis | 19% | 9% | 64% |
| Calorie Weighted Basis | 18% | 20% | 61% |
The first ingredient in this dog food is corn. Corn is an inexpensive and controversial cereal grain. And aside from its energy content, this grain is of only modest nutritional value to a dog.
For this reason, we do not consider corn a preferred component in any dog food.
The second ingredient is powdered cellulose, a non-digestible plant fiber usually made from the by-products of vegetable processing. Except for the usual benefits of fiber, powdered cellulose provides no nutritional value to a dog.
The third ingredient is chicken by-product meal, a dry rendered product of slaughterhouse waste. It’s made from what’s left of a slaughtered chicken after all the prime cuts have been removed.
In a nutshell, chicken by-products are those unsavory leftovers usually considered “unfit for human consumption”.
In addition to organs (the nourishing part), this stuff can contain almost anything — feet, beaks, undeveloped eggs — anything except quality skeletal muscle (real meat).
On the brighter side, by-product meals are meat concentrates and contain nearly 300% more protein than fresh chicken.
In any case, although this item contains all the amino acids a dog needs, we consider chicken by-products an inexpensive, lower quality ingredient.
The fourth ingredient is corn gluten meal. Gluten is the rubbery residue remaining once corn has had most of its starchy carbohydrate washed out of it.
Compared to meat, glutens are inferior grain-based proteins lower in some of the essential amino acids dogs need for life.
This inexpensive plant-based ingredient can significantly boost the total protein reported on the label — a factor that must be considered when judging the actual meat content of this dog food.
After the chicken liver flavor, we find soybean mill run. Mill run is a by-product, mostly the hulls of soybeans remaining after processing the beans into meal. This is nothing more than a cheap, low-quality filler more commonly found in cattle feeds.
The seventh ingredient is soybean oil is red flagged here only due to its rumored (yet unlikely) link to canine food allergies.
However, since soybean oil is high in omega-6 fatty acids and contains no omega-3′s, it’s considered less nutritious than flaxseed oil or a named animal fat.
The eighth ingredient is beet pulp. Beet pulp is a controversial ingredient, a high fiber by-product of sugar beet processing.
Some denounce beet pulp as an inexpensive filler while others cite its outstanding intestinal health and blood sugar benefits.
We only call your attention here to the controversy and believe the inclusion of beet pulp in reasonable amounts in most dog foods is entirely acceptable.
The ninth ingredient is lactic acid, a compound found naturally in many living organisms. It’s likely added here to adjust the pH of the product which (in turn) reduces the growth of unwanted biological contaminants.
From here, the list goes on to include a number of other items.
But to be realistic, ingredients located this far down the list (other than nutritional supplements) are not likely to affect the overall rating of this product.
With five notable exceptions…
First, soybean meal is a by-product of soybean oil production more commonly found in farm animal feeds.
Although soybean meal contains 48% protein, this ingredient would be expected to have a lower biological value than meat.
And less costly plant-based products like this can notably boost the total protein reported on the label — a factor that must be considered when judging the actual meat content of this dog food.
Next, caramel is a coloring agent made by caramelizing carbohydrates. It’s used by pet food manufacturers to impart a golden brown tint to the finished product.
Even though caramel is considered safe by the FDA, we’re always disappointed to find any added coloring in a pet food.
That’s because coloring is used to make the product more appealing to humans — not your dog. After all, do you really think your dog cares what color his food is?
In addition, flaxseed is one of the best plant sources of healthy omega-3 fatty acids. Provided they’ve first been ground into a meal, flax seeds are also rich in soluble fiber.
However, flaxseed contains about 19% protein, a factor that must be considered when judging the actual meat content of this dog food.
Next, we find no mention of probiotics, friendly bacteria applied to the surface of the kibble after processing to help with digestion.
And lastly, the minerals listed here do not appear to be chelated. And that can make them more difficult to absorb. Non-chelated minerals are usually associated with lower quality dog foods.
Hill’s Prescription Diet W/D Dog Food
The Bottom Line
Even though this is a prescription product, our review has nothing to do with the accuracy of claims made by the manufacturer as to the product’s ability to treat or cure a specific health condition.
So, to find out whether or not this dog food is appropriate for your particular pet, you must consult your veterinarian.
With that understanding…
Judging by its ingredients alone, Hill’s Prescription Diet W/D dog food looks like a below average dry product.
But ingredient quality by itself cannot tell the whole story. We still prefer to estimate the product’s meat content before concluding our report.
The dashboard displays a dry matter protein reading of 19%, a fat level of 9% and estimated carbohydrates of about 64%.
As a group, the brand features an average protein content of 19% and a mean fat level of 9%. Together, these figures suggest a carbohydrate content of 64% for the overall product line.
And a fat-to-protein ratio of about 46%.
Low protein. Low fat. And high carbohydrates when compared to a typical dry dog food.
When you consider the protein-boosting effects of the corn gluten and soybean meals and the flaxseed, this looks like the profile of a kibble containing just a limited amount of meat.
Bottom line?
Hill’s Prescription Diet W/D dog food is a plant-based kibble using only a limited amount of chicken by-product meal as its main source of animal protein.
However, due to its intentional therapeutic design, this dog food is not rated.
Special Alert
Rice ingredients can sometimes contain arsenic. Until the US FDA establishes safe upper levels for arsenic content, pet owners may wish to limit the total amount of rice fed in a dog's daily diet.
A Final Word
The descriptions and analyses expressed in this and every article on this website represent the views and opinions of the author.
Although it's our goal to ensure all the information on this website is correct, we cannot guarantee its completeness or its accuracy; nor can we commit to ensuring all the material is kept up-to-date on a daily basis.
Each review is offered in good faith and has been designed to help you make a more informed decision when buying dog food.
However, our rating system is not intended to suggest feeding a particular product will result in specific health benefits for your pet.
For a better understanding of how we analyze each product, please read our article, "The Problem with Dog Food Reviews".
Remember, no dog food can possibly be appropriate for every life stage, lifestyle or health condition. So, choose wisely. And when in doubt, consult a qualified veterinary professional for help.
In closing, we do not accept money, gifts or samples from pet food companies in exchange for special consideration in the preparation of our reviews or ratings.
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Have an opinion about this dog food? Or maybe the review itself? Please know we welcome your comments.
Notes and Updates
01/03/2010 Original review
08/08/2010 Review updated
11/13/2011 Review updated
05/15/2013 Review updated
05/15/2013 Last Update
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